Bergen-type rucksack

Here is a recent find - an unissued ABL (I am pretty sure at least) rucksack patterned after the classic British type. This one is made with olive drab canvas and webbing, with an interior rubber coating. I suspect it is a fairly late production, but I am not sure for how many years these packs were manufactured, or who was involved in producing them. There are no markings that I can see. It is a really high-quality item.